Material removal catheter and method

ABSTRACT

A catheter device that is useable to extract material from a body conduit, such as a blood vessel, comprises a flexible catheter advanceable into the body conduit, an opening in the wall of the catheter that is in fluid communication with a material collection chamber, and a controllably arcuate segment along the catheter shaft, near the distal tip of the catheter and including the opening. Further said catheter may include a sliding member, located within a lumen of the catheter, that is used to move the material entering the catheter through the arcuate segment opening, into the material collection chamber and away from said opening. The catheter may include a single mechanism utilized to both generate a vacuum to cause material to enter the catheter at the arcuate segment opening and also cause the sliding member to travel, inside the catheter, moving material away from the opening and into the material collection chamber. Methods of utilizing such a catheter device to remove material from a body conduit are also disclosed.

FIELD OF THE INVENTION

The present invention relates generally to medical devices, systems andmethods and more particularly to a material removal catheter and methodsthat are useable to remove thrombus and other undesired material fromthe vasculature or other internal conduit of a patient, the apparatusbeing particularly well suited for saphenous vein grafts, coronaryarteries and the peripheral vasculature.

BACKGROUND OF THE INVENTION

Human blood vessels often become partly or fully occluded by variousundesired materials including plaque, thrombi or other substances thatrestrict the flow of blood within the vessel. Depending on the locationof the occlusion, serious injury or even death can occur. Whendiagnosed, it is often advantageous to remove the occlusive material ina safe and effective manner. Coronary heart disease is an extremelycommon form of this occlusive disease, and is the leading cause of deathin the United States.

Arteriosclerosis is a chronic disease characterized by abnormalthickening and hardening of the arterial walls. As the coronary arteriesare first narrowed by plaque, at locations known as stenoses, furtherconstriction may be caused by the formation of blood clots, or thrombi,on the rough surface of the plaque. A severe complication ofarteriosclerosis is a myocardial infarction, or MI. An MI is the deathof a section of heart muscle when its blood supply is cut off, usuallyby a blood clot in a coronary artery narrowed by arteriosclerosis. An MIcan occur spontaneously due to severely narrowed vasculature or due toan embolus, such as a thrombus released from an upstream stenosis. Anembolus can even be caused in a medical procedure intended to reduce orremove a stenosis.

Various types of interventional techniques have been developed that canbe utilized to reduce or remove a blockage in a blood vessel. Onetechnique, known as balloon angioplasty, involves using a specialcatheter that includes a balloon near its distal tip, advancing theballoon into the constricted area, and inflating the balloon to expandthe constriction. Other therapeutic options include atherectomy,deployment of stents, infusion of therapeutic medications and heartbypass surgery. All of these therapeutic options involve the risk ofdislodging a portion of the occlusive material, causing embolus to movedownstream thus causing further complications.

Heart bypass surgery is an extremely invasive and traumatic form oftherapy to treat coronary occlusive disease. In one form of bypass, aportion of vein taken from the patient's leg, the saphenous vein, isconnected between the aorta and a portion of the blocked artery distalto the blockage, supplying oxygenated blood to the portions of heartmuscle supplied by the artery prior to its being occluded. Thesesaphenous vein grafts often used in heart bypass procedures are alsosusceptible to occlusive disease, and over time may become restricted byplaque and thrombus. Atherosclerotic plaque in saphenous vein graftstends to be softer and more friable than their arterial counterparts andthus more prone to embolizing during treatment.

Chemical thrombolytic drugs are available to treat saphenous vein graftsbut require the patient to be non-ambulatory throughout their use andhave numerous risks and complications. Balloon angioplasty of saphenousvein grafts is associated with a higher rate of embolus generation,potentially migrating downstream to block a portion of the coronaryartery to which it is attached and causing a myocardial infarction.Directional Coronary Atherectomy, or DCA catheters include cuttingblades that can damage the vessel wall and the systems have a propensityto become clogged and generate embolus similar to balloon angioplasty.Adjunctive devices are available to reduce the complications ofembolization by trapping the released emboli downstream. These devicesare expensive, and complicated to use. Vacuum extraction catheters havebeen developed to treat saphenous vein grafts, however they tend to belarge and bulky and have had sub optimal results and numerouscomplications.

Clearly, therefore, there is a need for improved devices, systems andmethods for removal of undesired material from an internal body conduitsuch as a saphenous vein graft or coronary artery that improve theefficiency of material removal and reduce the risks to the patient.

SUMMARY OF THE INVENTION

The present invention is directed to a device and method that simply andeffectively removes undesired material from the wall of a conduit, suchas a blood vessel. The device is a catheter with an elongate cathetershaft having a proximal end and a distal end. The distal end of thecatheter shaft has a diameter less than the conduit containing theundesired material, said catheter shaft including a controllably arcuateportion or segment which can be directed toward and make contact withthe undesired material prior to extraction. The controllably arcuatesegment includes one or more openings into which the material is drawnby applying a negative pressure, or suction from the inside of theopening. The controllably arcuate segment can be transformed into both arelatively straight and a relatively bowed geometry with operatorcontrols contained on the proximal end of the catheter device.

The catheter device of the present invention may be inserted intovarious body conduits including but not limited to blood vessels such ascoronary vessels, peripheral vessels, coronary bypass grafts andarteriovenous fistulas. The device may be used for diagnosticapplications, such as taking a material sample, or therapeuticapplications such as reducing an occlusion within a saphenous veingraft. The device can be used in various hospital and outpatientsettings, and can be guided using fluoroscopy and other imagingtechnologies. The device may include various markers or othervisualization elements, such as radiopaque fillings or bands, ultrasoundcrystals or ultrasonic markers, or other markers or indicators to aid inpositioning and use of the device. Such markers may include rotationalorientation markers to indicate the position of one or more openings inthe controllably arcuate segment. In addition or alternatively, thecatheter device may include an arcuate condition indicator providingvisual or other feedback to the operator as to the relatively straightor relatively bowed geometric conditions of the controllably arcuatesegment. In a preferred embodiment, an audio signal is provided, such aswhen the controllably arcuate segment is in the relatively bowedgeometry, to prevent the clinician from inadvertently advancing orotherwise moving the catheter shaft when the controllably arcuatesegment should be in a relatively straight geometry. In anotherpreferred embodiment, the catheter device includes a lumen, includedalong a minority or a majority of the length of the catheter shaft,through which a guidewire can be inserted for practice of over the wireinterventional techniques.

The openings in the controllably arcuate segment of the device are influid communication with one or more ports or chambers in the proximal,external portion of the device via one or more lumens. Within or at theend of the lumens may exist one or more valves oriented to permit flowof material in one direction only. Located in a distal portion of thecatheter, near to and in fluid communication with the openings is amaterial collection chamber. The material collection chamber is proximalor distal to the openings, and is in fluid communication with theproximal, aspirating portion of the device via a connecting lumen. In apreferred embodiment, the material collection chamber is the connectinglumen itself. Suction applied to the aspiration portion is communicatedto the openings in the controllably arcuate segment via the materialcollection chamber.

In a preferred embodiment, the aspiration chamber may be connected to awaste exit, such as by a one-way valve such that when positive pressureis applied, material collected in the aspiration chamber from theopenings in the controllably arcuate segment is evacuated from theaspiration chamber.

In a preferred embodiment, within a lumen of the catheter shaft is asliding member that is connected to a mechanical linkage extendingthrough the catheter shaft to the proximal portion of the device. Thelinkage is connected to sliding or other controls on the handle of thecatheter device for advancement and retraction of the sliding member. Ina preferred embodiment, the sliding member and mechanical linkageinclude a lumen permitting a guidewire to be placed through each. Thelinkage system may include one or more mechanical stops that limit theadvancement or retraction. In the fully advanced position, the tip ofthe sliding member, which preferably is tapered, extends beyond thedistal end of the catheter. The tip of the sliding member may extendbeyond the end of the catheter in the fully retracted position as well.The sliding member can be used to change the geometry of thecontrollably arcuate segment. In a preferred embodiment, thecontrollably arcuate segment is normally bowed, and placing the slidingmember within the lumen of the controllably arcuate segment changes thesegment into a relatively straight geometry. To facilitate the change inshape of the controllably arcuate segment, the sliding member isconstructed to be less flexible than the controllably arcuate segment.The sliding member, which may have a sharpened end that is orientedtoward the opening, is advanced or retracted to move toward the openingthereby cutting and or pushing material away from the opening and intothe material collection chamber. The one or more openings can havedifferent cross sectional profiles, such as round or oval perimeters, orvarious angles of tapers, and may change geometry based on the geometryof the controllably arcuate segment and or the position of the slidingmember. The material collection chamber may be located proximal ordistal to the opening of the controllably arcuate segment, whereby thesliding member is retracted or advanced respectively to move thematerial received through the opening into the material collectionchamber. In order to draw material from the outside of the cathetershaft through the opening in the controllably arcuate segment, anegative pressure or suction is applied at an opening on the proximalend of the catheter device. Aspiration or negative pressure may bemaintained during the period of time that the sliding member is advancedor retracted. The present invention includes various means of providingthe suction including connections to attach to syringes or sophisticatedvacuum and material collection generators as well as integratedaspiration systems. The present invention may include one or more valvesto prevent blood leakage, avoid over pressurization, allow one way flowof fluid and other material into or out of various chambers or otherlocations and other purposes.

In another preferred embodiment, the controllably arcuate segment has anormally bowed bias which is converted to a relatively straightgeometric shape by integral straightening means. The normally bowed biascan be created during manufacturing with catheter shaping processesknown to those of skill in the art, or with embedded curved stiffeners.The sliding member can function as the integral straightening means, asis described above, or an embedded element can change the controllablyarcuate segment from a relatively bowed to a relatively straightgeometry, on command, via controls located on the proximal portion ofthe device. In another preferred embodiment, the controllably arcuatesegment has a normally straight bias which is converted to a relativelybowed geometric shape by integral curving means. Various curving meansare described including mechanical pull wires or embedded curvingelements that are attached, such as via electrical wires, to controlmeans located on the handle on the proximal end of the device. Anembedded battery and a switch located on the handle are used to connectthe curving elements to a power source driving the shape change of thecurving element. Multiple states, or transitional geometric shapes maybe formed in the controllably arcuate segment in addition to a maximallystraight and a maximally bowed geometry. Curving elements may beconstructed of shaped memory components, such as shaped memory alloys orshaped memory polymers, piezo material, or electromagnet assemblies.Curving elements may have a filament shape, a tubular shape or anon-uniform shape. Curving elements may consist of single or multiplecomponents that cause the controllably arcuate segment of the cathetershaft to transform to the proper bowed geometry, thus positioning thecontrollably arcuate segment's opening up against the wall of the bodyconduit into which the catheter device of the present invention isinserted. Curving or straightening elements may work in combination witha sliding member to change the geometry of the controllably arcuatesegment. Changing curvature of the controllably arcuate segment cancause the openings in the segment to change shape including changingfrom a fluidly closed to a fluidly open state.

In a preferred embodiment, the proximal end of the catheter deviceincludes a handle with an integrated plunger assembly. Retraction of agrasper moves a syringe like shaft and plunger to create a negativepressure at the opening in the controllably arcuate segment. Inaddition, continued retraction continues the aspirating pressurescausing material to be drawn through one or more lumens in the catheterdevice to a chamber in the handle. Advancement of the grasper causesmaterial to evacuate the chamber through a waste exit. In thisparticular embodiment, the grasper may also advance or withdraw amechanical linkage connected to a sliding member which is used to severor otherwise move material away from the opening in the controllablyarcuate segment.

In a preferred embodiment, the catheter device includes a thru lumenfrom the proximal handle to the distal tip, such that material, such asthrombus, can be aspirated from the handle through the catheter shaftand removed from a location where the distal end of the catheterresides. Alternatively, a core assembly, such as an assembly includingthe mechanical linkage and sliding member, is removable wherein removalof the core creates the lumen that can be used to aspirate material fromthe distal end of the catheter. In another preferred embodiment, thecatheter device includes a lumen for injecting fluids, such asradiopaque dye or blood thinning agents, wherein the lumen is attachedto an input port on the handle of a the device and an exit located at ornear the distal end of the catheter device. The lumen can also be usedto extract material from the distal end of the catheter.

In another preferred embodiment, the catheter device includes anelongate catheter body with a proximal end and a distal end, anaspiration chamber located near the proximal end, a controllably arcuatesegment including at least one opening, and an aspiration lumen in fluidcommunication with the aspiration chamber and one or more openings inthe controllably arcuate segment. The device may include a slidingmember to move material drawn through the opening under pressure, awayfrom the opening. The device may have a normally bowed or a normallystraight bias. The device may further include one or more curvingelements, controllable from the proximal end of the catheter device, fortransforming the controllably arcuate segment from one geometric shapeto another.

A preferred method of using any of the catheter embodiments of thepresent invention is also disclosed. The method for removing materialfrom a biological conduit includes providing a catheter device having anelongate catheter shaft having a proximal end and a distal end, acontrollably arcuate segment including at least one opening in fluidcommunication with the proximal end and a sliding member that movesmaterial received through the arcuate segment opening away from saidopening. The device is percutaneously or surgically advanced into abiological conduit, preferably with the controllably arcuate segment ina relatively straight geometry, after which suction is applied to causenegative pressure at the one or more openings. The sliding member isthen retracted to move material away from the opening. The controllablyarcuate segment is changed to a relatively straight geometry prior toadvancing, retracting or rotating the catheter device. In anotherpreferred method, after the catheter device is used to first extractmaterial, it is rotated and additional material is removed, eachrotation accompanied by a predecessor step of changing to a relativelystraight geometry, and each extraction step accompanied by a predecessorstep of changing to a relatively bowed geometry.

Another preferred method is disclosed for removing material from abiological conduit comprising the steps of providing a catheter devicehaving an elongate catheter shaft having a proximal end and a distalend, a controllably arcuate segment including at least one opening influid communication with the proximal end, percutaneously or surgicallyinserting and transluminally advancing the catheter into the biologicalconduit, applying suction to the at least one opening in thecontrollably arcuate segment and changing the shape of the controllablyarcuate segment from a relatively bowed geometry to a relativelystraight geometry. Additional steps may include changing from arelatively bowed to a relatively straight geometry prior to insertion ofthe catheter device. The device may be changed from a relativelystraight geometry to a relatively bowed geometry prior to applyingsuction. Additional steps may include use of radiopaque markers toposition the device within the body conduit.

The present invention, therefore, provides a catheter device forremoving undesirable material, such as thrombus, from a body conduit,such as a saphenous vein graft or other blood vessel, including acontrollably arcuate segment which further includes an opening that canbe brought in contact with the undesired material with sufficient forcesuch than under suction, the material is drawn through the opening intoan lumen, cavity or chamber within the catheter device. The use of thedevice is simple and straightforward, and does not require bulky orexpensive equipment not otherwise included in the various hospitalsettings in which it will be used.

These aspects of the invention together with additional features andadvantages thereof may best be understood by reference to the followingdetailed descriptions and examples taken in connection with theaccompanying illustrated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a side view of a first exemplary embodiment of a catheterdevice constructed in accordance with the present invention showing acontrollably arcuate segment in a relatively straight geometry.

FIG. 1B is a side view of the device of FIG. 1A showing the controllablyarcuate segment in a relatively bowed geometry.

FIG. 2 is a cross-sectional view of the device of FIGS. 1A and 1Bshowing the opening in the controllably arcuate segment positioned at asite in a biological conduit prior to removal of occlusive material.

FIG. 3 is a cross-sectional view of a preferred embodiment of a catheterdevice constructed in accordance with the present invention.

FIG. 3A is an enlarged sectional view of the proximal end of thecatheter device contained in circle 3A of FIG. 3.

FIG. 3B is an enlarged sectional view of a distal end of the catheterdevice contained in circle 3B of FIG. 3.

FIG. 4 is a cross-sectional view of the catheter device of FIG. 3 shownwith a grasper of the handle assembly in a retracted position.

FIG. 4A is an enlarged sectional view of the proximal end of thecatheter device contained in circle 4A of FIG. 4.

FIG. 4B is an enlarged sectional view of the distal end of the catheterdevice contained in circle 4B of FIG. 4.

FIG. 5 is a cross-sectional view of another preferred embodiment of acatheter device constructed in accordance with the present invention.

FIG. 5A is an enlarged sectional view of the proximal end of thecatheter device of FIG. 5 shown with the grasper of the handle assemblyshown in a fully advanced position.

FIG. 5B is an enlarged sectional view of the proximal end of thecatheter device of FIG. 5 shown with the grasper of the handle assemblyshown in a partially retracted position.

FIG. 5C is an enlarged sectional view of the distal end of the catheterdevice of FIG. 5 shown with the sliding member in the partiallyretracted position corresponding to the grasper position of FIG. 5B.

FIG. 5D is an enlarged sectional view of the proximal end of thecatheter device of FIG. 5 shown with the grasper of the handle assemblyshown in a fully retracted position.

FIG. 5E is an enlarged sectional view of the distal end of the catheterdevice of FIG. 5 shown with the sliding member in the fully retractedposition corresponding to the grasper position of FIG. 5D.

FIG. 5F is an enlarged sectional view of the proximal end of thecatheter device of FIG. 5 shown with the grasper of the handle assemblyshown in a partially advanced position.

FIG. 5G is an enlarged sectional view of the distal end of the catheterdevice of FIG. 5 shown with the sliding member in the a partiallyadvanced position corresponding to the grasper position of FIG. 5F.

FIG. 6 is a cross-sectional view of another preferred embodiment of acatheter device constructed in accordance with the present invention.

FIG. 6A is an enlarged sectional view of the distal end of the catheterdevice of FIG. 6 shown with the controllably arcuate segment in arelatively straight geometric shape.

FIG. 6B is an enlarged sectional view of the distal end of the catheterdevice of FIG. 6 shown with the controllably arcuate segment in arelatively bowed geometric shape.

FIG. 7 is an enlarged sectional view of the distal end of anotherpreferred embodiment of the catheter device of the present invention.

FIG. 8 is an enlarged sectional view taken along line A-A of FIG. 7showing a preferred configuration of a curving element.

FIG. 9 is an enlarged sectional view taken along line A-A of FIG. 7showing another preferred configuration of a curving element.

FIG. 10 is an enlarged sectional view taken along line A-A of FIG. 7showing yet another preferred configuration of a curving element.

Like reference characters designate identical or correspondingcomponents and units throughout the several views.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring first to FIGS. 1A and 1B, there is illustrated an exemplaryembodiment of a catheter device 10 constructed in accordance with thepresent invention. The catheter device 10 includes a catheter shaft 20constructed of materials that are biocompatible and also permitflexibility of the device required to allow insertion into andadvancement through the vasculature of a patient. Catheter shaft 20contains one or more hollow lumens within its structure that allow flowof material such as blood or thrombus, as well as permit controllingshafts, mechanical linkages or flexible tubes or wires to slide back andforth. Fixedly attached to the proximal end of catheter shaft 20 is ahandle, handle 70, which allows the user to advance and maintain theposition of the distal end of catheter device 10, as well as rotate thecatheter shaft 20.

Handle 20 includes aspiration port 75 that is in fluid communicationwith an internal lumen of catheter shaft 20. Aspiration port 75 can beconnected to various means of creating a vacuum or suction, such as avacuum generator or simple syringe. Aspiration port 75 may includestandardized threads, such as standard luer threads, or other mechanicalconnection means to facilitate connection to the suction means, notshown. Aspiration port 75 is in fluid communication with a hollow lumenof catheter shaft 20 via a similar lumen, opening or cavity withinhandle 70, all not shown, but described in detail in subsequent figures.Exiting handle 70 is a mechanical linkage, linkage 30 which terminatesat its proximal end with a separate handle for the user to grasp,grasper 60. Advancement and retraction of grasper 60 causes similarlinear motion of linkage 30 that is slidingly received through thehandle 70 and into catheter shaft 20.

Attached to the distal end of linkage 30 is a cylindrical element,sliding member 100. Preferably, both linkage 30 and sliding member 100contain a thru lumen such that a standard interventional guidewire canbe inserted therethrough, and catheter device 10 advanced and retractedover the guidewire using standard interventional over the wiretechniques. The combined lengths of linkage 30 and sliding member 100are preferably chosen such that when grasper 60 is in both a fullyadvanced and a fully retracted position, the distal tip of slidingmember 100 exits the distal end of catheter shaft 20. Preferably, thedistal end of sliding member 100 is tapered to allow atraumaticadvancement of catheter device 10 through the vasculature or other bodyconduits.

Near the distal end of catheter shaft 20 is controllably arcuate segment40, a finite length of shaft 20, proximal to the tip of catheter device10, that can be controlled by the user to transform on command from arelatively straight geometry or shape, to a relatively bowed, or arcuategeometry. Included at or near the mid-portion of controllably arcuatesegment 40 is a hole, opening 50, which traverses from the outer surfaceof shaft 20 to an internal cavity contained within shaft 20. Referringspecifically to FIG. 1A, grasper 60 and sliding member 100 are shown ina retracted position, and the controllably arcuate segment 40 is shownin a relatively straight geometry. Referring now to FIG. 1B, grasper 60and sliding member 100 are shown in a fully advanced position, and thecontrollably arcuate segment 40 is shown in a relatively bowed geometry.There are various means of achieving control of the shape ofcontrollably arcuate segment 40 including embodiments in which thecontrollably arcuate segment 40 is normally bowed and means are providedfor transforming to a relatively straight geometry, as well asembodiments in which the controllably arcuate segment 40 is normallystraight, and means are provided for transforming to a relatively bowedgeometry. Numerous means of controlling the shape of controllablyarcuate segment 40 for FIGS. 1A and 1B as well as additional figures aredescribed in detail herebelow.

FIGS. 1A and 1B depict a preferred embodiment in which a controllablyarcuate segment 40 is simply a portion of catheter shaft 20 that hasbeen formed or shaped in its manufacturing process to have a relativelybowed geometry. A common process for catheter shaping includes insertinga pre-shaped metal mandrel in the catheter during manufacture, andheating the device with the mandrel in place. The mandrel length andshape geometry would be designed to cause the proper bow at the properlocation along the catheter shaft 20. After a cooling time, the mandrelis removed and the catheter assumes the desired shape. This process isoften used to form complex catheter tip shapes common to variouscardiovascular guide catheters, and is an effective way of shaping anelastomeric tube with one or more internal lumens. In FIGS. 1A and 1B,the sliding member 100 acts as the means of transforming the normallybowed controllably arcuate segment 40 from its manufactured bowedgeometry to a relatively straight geometry. When the sliding member 100is advanced beyond the length of the controllably arcuate segment 40,controllably arcuate segment 40 assumes its bowed configurationestablished during the manufacturing process. The material selection,thickness and other geometric parameters of sliding member 100 arechosen such that when grasper 60 is retracted, linkage 30 retractssliding member 100 accordingly, causing a significant length of slidingmember 100 to reside within the internal lumen of controllably arcuatesegment 40, further causing controllably arcuate segment 40 to transforminto a relatively straight geometry. When the grasper 60 and attachedlinkage 30 are advanced, the majority of length of sliding member 100slides out of the internal lumen of controllably arcuate segment 40,allowing it to reassume its bowed geometry. Subsequent advancement andretraction of grasper 60, correspondingly advances and retracts linkage30 and sliding member 100 such that controllably arcuate segment 40transforms to a relatively bowed geometry to a relatively straightgeometry respectively.

Referring again to FIGS. 1A and 1B, there is included near the midpointof controllably arcuate segment 40 an hole, opening 50, which extendsfrom the outer surface of catheter shaft 20 to an inner lumen. Asdescribed above, aspiration port 75 is in fluid communication with aninternal lumen of catheter shaft 20, this particular lumen also in fluidcommunication with opening 50 such that when a vacuum is applied toaspiration port 75 by way of a syringe or other means, suction isapplied at opening 50 causing material in close proximity to opening 50to be drawn into the lumen of shaft 20 via opening 50. Controllablyarcuate segment 40 construction materials and geometry and the geometryof opening 50 may be chosen such that when controllably arcuate segment40 is in its relatively bowed geometry, opening 50 is relatively open,however when controllably arcuate segment 40 is in its relativelystraight geometry, opening 50 is relatively closed.

Referring now to FIG. 2, a preferred method of utilizing catheter device10 is depicted. The catheter device 10 of the present invention can beplaced percutaneously or intraoperatively, and advanced through a bodyconduit such as the vascular system. In a preferred embodiment, catheterdevice 10 is inserted percutaneously into the vasculature to treat ablood vessel, such as a coronary vessel or saphenous vein graft placedduring coronary artery bypass graft surgery. Typically a guide catheter,not shown, is placed at a convenient vascular access point such as afemoral artery, and advanced to a point proximal to a stenotic locationsuch as the ostium of an occluded saphenous vein graft. Typically aguidewire, such as an 0.014 inch guidewire, guidewire 300, is advancedthrough the guide catheter and into the lumen of the vessel to betreated to a location past the stenosis.

Next the catheter device 10 of the present invention is percutaneouslyinserted and transluminally advanced through the guide catheter and overguidewire 300 into the vessel to be treated, blood vessel 200,positioning the opening 50 of the controllably arcuate segment 40 nearthe area of occlusive material to be removed, occlusive material 210.Each time the catheter device 10 is inserted with the controllablyarcuate segment 40 in the relatively straight geometric condition, shownin FIG. 2 at a later step with the controllably arcuate segment 40 inthe relatively bowed geometry. The operator would assure and or changeto that relatively straight geometry condition not only prior toinsertion, but each time the device is transluminally advanced,withdrawn or rotated. In this particular embodiment, the catheter deviceof FIGS. 1A and 1B, the operator would simply retract grasper 60 tocause the controllably arcuate segment 40 to be in the relativelystraight geometric shape. Other means for changing the shape ofcontrollably arcuate segment 40 are described with the subsequentfigures below. Catheter shaft 20 has a length appropriately chosen suchthat a small portion of the proximal end of catheter shaft 20 extendsout of the guide catheter, placing handle 70 in close proximity to theinsertion site, when opening 50 is properly positioned at the locationof the occlusive material 210.

The axial position of the guide catheter, guidewire 300 and variouscomponents of catheter device 10 are known within the vessel utilizingconventional techniques and equipment which may include, for example,fluoroscopy, ultrasound, nuclear magnetic resonance imaging (NMR), andother visualization techniques and equipment commonly found in hospitaloperating rooms, catheterization laboratories and other therapeutic anddiagnostic environments. In a preferred embodiment, catheter shaft 20can be visualized with visualization equipment such as fluoroscopy, orcatheter shaft 20 has been modified to be visualized. Insertion ofradiopaque agents, such as barium sulfate, in small amounts, allowsrelatively thin catheter shafts to be visualized with x-ray equipmentsuch as fluoroscopy. Various surface modification or air bubbleimpregnation techniques can be employed to make the implantablematerials be visualized with ultrasound and other modifications can beaccomplished to be compatible with other visualization technologies.Catheter shaft 20 and controllably arcuate segment 40 shall be modifiedsuch that the user can differentiate when the controllably arcuatesegment 40 is in its relatively straight geometry versus its relativelybowed geometry. In a preferred embodiment, a visualization marker,marker 51, preferably a radiopaque band, is also included near orsurrounding opening 50 such that during rotation of catheter shaft 20,the angular orientation as well as the longitudinal positioning ofopening 50 can be visualized. Additionally, the catheter device 10 mayinclude an internal lumen or pathway, not shown, that allowsangiographic dye to be injected into it, exiting at a point at or nearthe distal tip of catheter shaft 20, such as through the guidewirelumen, around the guidewire lumen, or through opening 50.

Referring still to FIG. 2, the catheter device 10 has beentransluminally advanced over guidewire 300 such that opening 50 has beenpositioned near the occlusive material 210. Note that at this point inthe procedure, controllably arcuate segment 40 remains in the relativelystraight geometry, not depicted in FIG. 2, that it has maintainedthrough the entire insertion process thus far. At this time, theoperator transforms the controllably arcuate segment 40 from therelatively straight geometry to the relatively bowed geometry depictedin FIG. 2. With the particular embodiment of FIGS. 1A and 1B, theoperator would simply advance the grasper 60 to its fully advancedposition. The outside diameter of catheter shaft 20 is chosen to besomewhat less than the inner diameter of the vessels it is advancedthrough, including the vessel diameter at the stenosis. The radius ofcurvature and length of controllably arcuate segment 40 in its maximallybowed geometric shape is chosen such that opening 50 is pushed againstthe occlusive material with some amount of force. Catheter device 10will be manufactured with not only various lengths and diameterprofiles, but numerous radii of curvature and segment lengths forcontrollably arcuate segment 40, to accommodate a range of body conduitsto be treated, specifically blood vessels such as saphenous vein grafts.Catheter diameters, lengths and other geometric criteria are chosenbased on the path from the percutaneous entry site to the treatmentsite, as well as the size and geometry of the vessel to be treated andthe size and geometry of the occlusive material to be removed. In itsmaximally bowed geometry depicted in FIG. 2, the opening 50 ofcontrollably arcuate segment 40 is positioned such that as suction isapplied via aspiration port 75, occlusive material 210 is drawn into aninternal cavity of catheter shaft 20. In a preferred embodiment,controllably arcuate segment 40 at the general area of opening 50 wouldplace a small amount of force against the occlusive material when thecontrollably arcuate segment 40 is in its relatively bowed geometricshape.

A next step for the operator is to retract grasper 60 causing linkage 30and thus sliding member 100 to also retract. As sliding member 100retracts, its proximal end pushes, potentially cutting, materialprojecting through opening 50 to a location away from the opening, moreproximal to the aspiration port 75. Vacuum or suction may be maintainedduring the retraction of sliding member 100. Optionally, grasper 60 canbe advanced again, advancing linkage 30 and sliding member 100 causingcontrollably arcuate segment 40 to change from a relatively straightgeometry to a relatively bowed geometry and positioning opening 50 againagainst any remaining occlusive material 210. Suction can be reapplied,and grasper 60 again retracted, once again moving any materialprotruding through opening 50 away from opening 50, as well as causingcontrollably arcuate segment 40 to change from a relatively bowedgeometry to a relatively straight geometry.

When the controllably arcuate segment 40 has been placed in itsrelatively straight geometry, the catheter device 10 can be removed byretracting it back over guidewire 300 and out through the guide catheterleaving guidewire 300 and the guide catheter in place. Alternatively,also when the controllably arcuate segment 40 has been placed in itsrelatively straight geometry, the handle 70 can be rotated causingcatheter shaft 20 to also rotate. When opening 50 is rotated to itsdesired angular position, as may be determined using fluoroscopy andmarker 51, grasper 60 can be advanced, again causing controllablyarcuate segment 40 to change to its relatively bowed condition andsimultaneously positioning opening 50 with a minimal level of forceagainst additional occlusive material. Suction can again be applied,causing additional material to be drawn through opening 50, and grasper60 can then be retracted, causing linkage 30 and thus sliding member 100to simultaneously retract similarly pushing the additional materialprotruding through opening 50 away from opening 50 as well as causingcontrollably arcuate segment 40 to change from a relatively bowedgeometry to a relatively straight geometry.

A preferred method includes the steps of 1) changing controllablyarcuate segment 40 to its relatively bowed shape; 2) applying suction;3) retracting grasper 60 and thus also retracting sliding member 100; 4)advancing grasper 60 and thus also advancing sliding member 100simultaneously causing controllably arcuate segment 40 to change back toa relatively straight geometry and 5) rotating handle 70 and thuscatheter shaft 20. These steps can be repeated through a 360 degreerotation or more to remove undesired material present along the luminalwalls of a body conduit. In addition to the above steps, longitudinalpositioning, forward or back, may also be performed, again only with thecontrollably arcuate segment 40 in its relatively straight geometriccondition. It should be noted that it might not be necessary to changethe controllably arcuate segment 40 from a bowed condition to amaximally straight geometry for some forms of repositioning such asrotation or transluminal advancement or retraction. Partialstraightening may suffice. Also, the above description include twodistinct shapes for controllably arcuate segment 40, it should be notedthat modifications to the controlling means, such as grasper 60, linkage30 and sliding member 100 described hereabove, can be made to allow theoperator to place controllably arcuate segment 40 in multipletransitional shapes from a maximally bowed geometry to a maximallystraight geometry.

Although this system was described specifically for a saphenous veingraft, it is readily applicable to any stenosis of a vessel or otherapplicable tubular conduit in the body. For example, the catheter device10 could be used to open stenoses in the other coronary vessels, acarotid artery, dialysis fistulas, peripheral vasculature, etc. Althoughthe present invention has only been described for the removal of plaqueor thrombus, the catheter device 10 could also be used to remove otherstenotic or occluding material or tissue from ducts such as the uretersor the fallopian tubes. Mammalian patients would include both humans andother animal patients.

FIGS. 3, 3A and 3B show another preferred embodiment of catheter device10 which is similar to the catheter device of FIGS. 1A and 1B withgrasper 60, linkage 30 and sliding member 100 all in a fully advancedposition and controllably arcuate segment 40 in its maximally bowedgeometry. Accordingly, elements of this embodiment which are similar toelements of catheter device 10 of FIGS. 1A and 1B are referenced withthe same reference numerals. Referring specifically to FIG. 3, catheterdevice 10 includes an aspiration chamber 72 included in handle 70.Catheter shaft 20 is fixedly attached to handle 70 while creating afluid path from aspiration port 75, into aspiration chamber 72 andcontinuing through aspiration lumen 21 to material collection chamber90. Material collection chamber 90 is in fluid communication withopening 50 of controllably arcuate segment 40. As shown in FIG. 3,material collection chamber 90 may be a simple continuation ofaspiration lumen 21, or material collection chamber 90 may have aspecific geometry or cavity-like structure while still in fluidcommunication with aspiration lumen 21.

Present within an internal lumen of catheter shaft 20 is a flexibleshaft, linkage 30, which is preferably a hollow tube permitting aguidewire to be inserted through its internal lumen, linkage lumen 31.Linkage 30 may be constructed of a flexible metal, such as a flexiblesteel hypotube, or a superelastic material such as Nitinol, a nickeltitanium alloy in its superelastic state. Alternatively, linkage 30 maybe constructed of a flexible plastic tube. As shown in FIGS. 3 and 3A,an opening around linkage 30 provides fluid communication betweenaspiration chamber 72 and aspiration lumen 21. At its proximal end,linkage 30 is fixed to grasper 60 that controls the advancement andretraction of linkage 30 and its connected components. Linkage 30 isfixed at its distal end to sliding member 100. The grasper 60, linkage30 and sliding member 100 are shown in the fully advanced position andthe controllably arcuate segment 40 is shown in a maximally bowedgeometry.

Referring additionally to FIG. 3A, grasper 60 surrounds and is fixedlyattached to linkage 30. The proximal end of linkage 30 includesguidewire opening 32 into which a guidewire can be placed and from whicha guidewire can exit. Linkage lumen 31 may include a valve, not shown,in its path to prevent leakage of blood once inserted. Alternatively,the diameter of linkage lumen 31 is chosen to be as small as possible,slightly larger than the outside diameter of the guidewire it is to beplaced over. Linkage 30 enters handle 70 such that a relatively fluidtight seal is created. In order to prevent fluid leakage, a sealingelement, linkage seal 71, is included that preferably consists of anelastomeric o-ring which seals between handle 70 and linkage 30 yetallows linkage 30 to slide back and forth as grasper 60 is advanced andretracted. Linkage 30 may include a mechanical stop, such as linkagestop 35, included on the outer diameter of linkage 30 to limit themaximum retraction distance of grasper 60. Linkage stop 35 is positionedalong the outer diameter of linkage 30 such that when grasper 60 isretracted, linkage stop 35 makes contact with the inside surface ofaspiration chamber 72 and linkage seal 71 limiting further retraction.At this maximally retracted state, shown in FIGS. 4, 4A and 4B, slidingmember 100 is positioned within controllably arcuate segment 40.

As shown in FIG. 3A, aspiration port 75 may include a valve, connectorvalve 76, such that when the attachable vacuum source, such as a vacuumgenerator or syringe, is not attached, fluid will not leak out ofaspiration chamber 72. Aspiration lumen 21 is in fluid communicationwith aspiration chamber 72 through a clearance around linkage 30 and anopening in the distal end of handle 70 inside of the attachment pointfor catheter shaft 20.

Referring additionally to FIG. 3B, Sliding member 100 includes a thrulumen continuing the guidewire clearance lumen provided by linkage 30.At the distal end of sliding member 100 is guidewire exit 33, whichallows the guidewire to be inserted into or exit from the device duringover the wire procedures. FIGS. 3, 3A and 3B show grasper 60 in itsfully advanced position, and FIG. 3 b depicts the corresponding locationof sliding member 100 in its fully forward or advanced position withcontrollably arcuate segment 40 shown in its maximally bowed geometry.Located at the midpoint of controllably arcuate segment 40 is opening 50that creates a fluid path from the outer portion of controllably arcuatesegment 40 to material collection chamber 90. Opening 50 is sized toallow collection of occlusive material, such as thrombus, utilizingvarious applicable vacuum pressures. Opening 50 may be a single hole ormultiple holes, the holes may be round, oval or other shape. The holesmay be of uniform geometry from inside to outside, or the holes may betapered or transform in shape as they pass through the wall ofcontrollably arcuate segment 40. Furthermore, opening 50 may be designedsuch that an open fluid path is created only when controllably arcuatesegment 40 is in a relatively bowed geometry and the fluid path throughopening 50 is closed or near closed when controllably arcuate segment 40is in a relatively straight geometry.

In a preferred embodiment, controllably arcuate segment 40 is normallybowed and is transformed to a relatively straight geometry when slidingmember 100 is retracted to reside within the lumen of controllablyarcuate segment 40. Controllably arcuate segment 40 can be normallybowed by a treatment, such as a heat treatment, in the manufacturingprocess as has been described hereabove, via embedded curving elementsin or near the controllably arcuate segment 40 or via other curvingmeans. Various designs for curving elements can be provided such asinternal curving or bending members, the details of which are describedin subsequent embodiments in detail herebelow.

FIGS. 4, 4A and 4B show the catheter device 10 of FIGS. 3, 3A and 3Bwith grasper 60, linkage 30 and sliding member 100 all in a fullyretracted position and controllably arcuate segment 40 in its maximallystraight geometry. Accordingly, elements of this embodiment which aresimilar to elements of catheter device 10 of FIGS. 3, 3A and 3B arereferenced with the same reference numerals. Referring specifically toFIG. 4, grasper 60 has been pulled back from its advanced position adistance equal to retraction distance RD. Accordingly, linkage 30 andsliding member 100 have also traveled in a direction toward the proximalend and away from the distal end of catheter device 10 an equivalentdistance equal to retraction distance RD. Referring additionally to FIG.4A, the amount of retraction distance is limited by a radial projection,linkage stop 35, which is fixedly attached to linkage 30 and stopsfurther retraction when linkage stop 35 contacts linkage seal 71 and orthe proximal end of aspiration chamber 72. Referring additionally toFIG. 4B, sliding member 100, in its fully retracted position, has itsproximal portion fully contained within an internal lumen ofcontrollably arcuate segment 40 causing controllably arcuate segment 40,which is naturally biased to be in a relatively bowed geometry, to betransformed into a relatively straight geometry. Sliding member 100 maybe made from a material more rigid than the material of catheter shaft20, such as a metal or a more rigid plastic or elastomer, and or itsgeometric construction chosen such that controllably arcuate segment 40is straightened by the straight sliding member 100 in its fullyretracted position. Sliding member 100 preferably includes a thru lumenwith an exit, guidewire exit 33, that is coaxial with a linkage lumen 31which is a thru lumen of linkage 30.

As grasper 60 is withdrawn from its fully advanced position, as shown inFIGS. 3, 3A and 3B, to its fully retracted position, as shown in FIGS.4, 4A and 4B, the proximal end, cutting end 101 of sliding member 100retracts toward and reaches opening 50 of controllably arcuate segment40. With suction applied at aspiration port 75 and communicated toopening 50 via aspiration lumen 21 and material collection chamber 90,loose material near the outside surface of catheter shaft 20 in theregion of opening 50 will be pulled through opening 50 to the inside ofcatheter shaft 20. As grasper 60 is continually retracted, and slidingmember 100 continues to retract past opening 50, the material pulledthrough opening 50 by the suction is cut and or pushed by sliding member100 away from opening 50 further into material collection chamber 90.Simultaneous with the retraction of sliding member 100 is thetransformation of controllably arcuate segment 40 from a relativelybowed geometry to a relatively straight geometry. FIGS. 3 and 3B andFIGS. 4 and 4B show a controllably arcuate segment 40 with a symmetricalgeometry, specifically wherein opening 50 is at the midpoint of thesemicircle of controllably arcuate segment 40 and the two arcs on eitherside of opening 50 have the same radius of curvature and length. Itshould be appreciated, and considered within the scope of thisapplication, that various other non-symmetrical geometries areapplicable, and may be preferred, such as a geometry wherein thecontrollably arcuate segment 40 has been minimally straightened whensliding member 100 reaches opening 50 and the majority of straighteningof controllably arcuate segment 40 occurs when sliding member 100 isfurther retracted to the maximum retraction of grasper 60.

Opening 50 is covered and may be sealed by sliding member 100 whengrasper 60, linkage 30 and sliding member 100 are in their fullyretracted position as is limited by linkage stop 35 and sliding member100 has its proximal portion contained within controllably arcuatesegment 40. Continued application of vacuum or aspiration at aspirationport 75 for the purpose of evacuating the material severed by cuttingend 101 of sliding member 100 and contained in material collectionchamber 90 may best be accomplished with inclusion of an additional thrulumen, not shown, to aspiration lumen 21 such that a circulatory path isprovided to properly flush out the material from collection chamber 90through aspiration lumen 21 and into aspiration chamber 72 where it canthen be evacuated into the vacuum source connected to aspiration port75. Note that in FIGS. 3, 3A, 3B, 4, 4A and 4B aspiration lumen 21 andmaterial collection chamber 90 are a continuous cross-section lumen withmaterial collection chamber 90 simply the part of that lumen closest toopening 50 of controllably arcuate segment 40. It should be understood,and it may be desirable, for material collection chamber 90 to have alarger cross sectional area than aspiration lumen 71, or to have otheralternative shapes to facilitate the collection of body material that ispushed into material collection chamber 90 each time 1) vacuum isapplied to aspiration port 75 with opening 50 positioned at a targetstenotic location of a vessel; 2) controllably arcuate segment 40 is ina relatively bowed geometry; and 3) sliding member 100 is retracted.

FIGS. 5 and 5A thru 5G show another preferred embodiment of the catheterdevice of the present invention which is similar to the catheter device10 of FIGS. 1A and 1B further comprising an integral aspiration orvacuum assembly and a connected waste receptacle. Accordingly, elementsof this embodiment which are similar to elements of catheter device 10of FIGS. 1A and 1B are referenced with the same reference numerals.Referring specifically to FIG. 5, catheter device 10A includes acatheter shaft 20 which is fixedly attached to handle 70 and includesone or more lumens extending from the proximal end to a point at or nearthe distal end, and may additionally include enclosed cavities orchambers which may be used to store collected occlusive material. Achamber within handle 70, aspiration chamber 72 includes a syringe-likepiston and plunger, plunger assembly 65. A flexible linkage, linkage 30,exits the proximal end of handle 70 and continues through an internallumen of catheter shaft 20 and is connected at its distal end to slidingmember 100, shown in FIG. 5 in its fully advanced position. Linkage 30contains a lumen therethrough, linkage lumen 31, which is sized to fitover a standard guidewire, such as an 0.014 guidewire. Linkage lumen 31includes an opening at its proximal end, guidewire opening 32.

Controllably arcuate segment 40, shown in its maximally bowed geometry,is again showed with a normally curved bias which can be caused bynumerous means such as those described in detail hereabove andherebelow. Alternatively, controllably arcuate segment 40 may have anormally straight bias, with shape control means changing controllablyarcuate segment 40 to a bowed bias as is shown and described in detailin subsequent figures and their detailed descriptions providedherebelow. Controllably arcuate segment 40 has, near its midsection, anopening 50 which traverses from the outside surface of controllablyarcuate segment 40 to an internal lumen in fluid communication with achamber, material collection chamber 90, used to store previouslyocclusive material, such as thrombus, which has been drawn via suctionthrough opening 50 when the controllably arcuate segment 40 is in arelatively bowed geometry. Material collection chamber 90 is shown influid communication with a lumen of catheter shaft 20, aspiration lumen21, which is in fluid communication with aspiration chamber 72.

Alternatively, not shown, material collection chamber 90 may be acaptured cavity, in fluid communication with opening 50 only, sized tostore an appropriate amount of extracted occlusive material. In thisparticular embodiment, aspiration lumen 21 would be fluidly connected toopening 50 to permit aspiration, or an applied vacuum, to opening 50 todraw the occlusive material through opening 50, and may include a valve,such as a flap valve, also not shown, to isolate aspiration lumen 21from opening 50 and or material collection chamber 90 when a suction isnot applied via aspiration lumen 21. Such a valve would preventcollected material from being drawn into the aspiration lumen 21 fromthe material collection chamber 90 when suction is applied to aspirationlumen 21. Similar to previous embodiments, when sliding member 100 iswithdrawn, the protruding occlusive material would be pushed into theclosed cavity material collection chamber 90.

Still referring to FIG. 5, aspiration chamber 72 has an attachedevacuation chamber, waste chamber 80, connected to aspiration chamber 72via waste exit 81. Referring additionally to FIG. 5A, plunger assembly65 includes a longitudinal shaft, plunger shaft 61 which is fixedlyconnected on its proximal end to grasper 60 and includes on its distalend a flexible covering, plunger 66, which forms a seal with the innerwalls of aspiration chamber 72. Preferably, aspiration chamber 72 has acircular cross section, however other cross sections are viableincluding oval, rectangular as well as asymmetrical cross sections. Thecross section of aspiration chamber 72 is uniform along, at a minimum,the length of travel of plunger assembly 65 in which plunger 66 contactsthe inner walls of aspiration chamber 72. Plunger shaft 61 is made froma rigid material such as a rigid plastic commonly used in standardsyringes, and the distal end of plunger shaft 61 has a shapeapproximating the shape of the cross-section of aspiration chamber 72.Plunger 66 covers the distal end of plunger shaft 61 and is preferablymade of a flexible material such as rubber or other material withproperties to facilitate a fluid seal between the plunger assembly 65and the walls of aspiration chamber 72. Plunger 66 is shown as acovering for a disk-like projecting end of plunger shaft 61 but itshould be understood that various other geometries could be utilized toform the desired seal including a simple notch along the outer diameterof plunger shaft 61 wherein plunger 66 is a standard O-ring.

As shown specifically in FIG. 5A, catheter shaft 20, preferably ofcircular cross section, is mechanically attached to handle 70.Aspiration lumen 21 is in fluid communication with an internal cavity ofhandle 70, aspiration chamber 72 via handle aspiration lumen 78. Handleaspiration lumen 78 may include a one way valve, such as a duck-billvalve, aspiration valve 79 shown. Aspiration valve 79 allows fluid andmaterial to pass from material collection chamber 90 and aspirationlumen 21 into aspiration chamber 72 when negative pressure or suction isapplied within aspiration chamber 72 however prevents material fromentering aspiration lumen 21 when positive pressure is applied withinaspiration chamber 72. Negative pressure is created when plungerassembly 65 is retracted by the operator, and positive pressure iscreated when plunger assembly 65 is advanced. When positive pressure iscreated, liquid and material collected in aspiration chamber 72 exits towaste chamber 80 via waste exit 81. Waste chamber 80 may be a rigid orpreferably flexible container such as a flexible bag or pouch. Wasteexit 81 may be a piece of tubing, attached to handle 70 to cause a fluidpath to aspiration chamber 72. Waste exit 81 may include an integratedone way valve, waste valve 82, such as a duck-bill valve similar inconstruction and performance to aspiration valve 79. When plungerassembly 65 is advanced by advancing grasper 60, the positive pressurecreated drives the liquid and other material from aspiration chamber 72into waste exit 81 and eventually waste chamber 80. Waste chamber 80 mayinclude a vent, not shown.

Plunger shaft 61 includes a lumen therethrough, which provides someclearance around linkage 30. Plunger shaft 61 further includes aprojection, shaft projection 62, extending radially inward from plungershaft 61 while making minimal or no contact with the outer surface oflinkage 30. Linkage 30 includes a projection, linkage projection 36extending radially outward from linkage 30 while making minimal or nocontact with the inner surface of plunger shaft 61. The projections,linkage projection 36 and shaft projection 62 are positioned to cause aspecific series of coordinated and timed linear movements of linkage 30and sliding member 100 as grasper 60 and connected plunger assembly 65are advanced and retracted by the operator. The linear movements aredescribed in detail herebelow with reference to FIGS. 5A thru 5G. Asshown in FIGS. 5 and 5A, grasper 60 and plunger assembly 65 is shown inits maximally advanced positioned, advanced position P1. Linkage 30 andsliding member 100 are also in their maximally advanced position ascaused by shaft projection 62 forcing linkage projection 36 forward.Plunger 66 has a surface, proximal edge 67, which faces linkageprojection 36 and when plunger assembly 65 is in advanced position P1,proximal edge 67 is offset from linkage projection 36. Grasper 60 ismaximally advanced when it makes contact with handle 70. Linkage 30 mayinclude another projection, linkage stop 35A, to limit advancement oflinkage 30. Linkage stop 35A also extends radially outward andpositioned along linkage 30 to limit forward travel by making contactwith the distal end of aspiration chamber 72. Each of the projections,linkage stop 35A, linkage projection 36 and shaft projection 62 may havea ring-like structure fully surrounding their appropriate shafts or maybe one or more rectangular projections.

Referring now to FIGS. 5B and 5C, Grasper 60 has been partiallyretracting causing partial retraction of plunger assembly 65 tointermediate position P2. During retraction, negative pressure iscreated in aspiration chamber 72 and this suction is communicated fromaspiration chamber 72 through handle aspiration lumen 78 and itsinternal valve, aspiration valve 79, into aspiration lumen 21, throughmaterial collection chamber 90 to opening 50. Fluid communication, inother words the effect of the negative pressure, is cut off from wasteexit 81 by the action of waste valve 82 oriented to prevent flow fromwaste exit 81 into aspiration chamber 72. Since proximal edge 67 hasjust made contact with linkage projection 36, movement of plungerassembly 65 from advanced position P1 to intermediate position P2 hasnot caused any retraction of linkage 30, therefore sliding member 100has not moved, and controllably arcuate segment 40 remains in its bowedgeometry. When appropriately placed in a blood vessel for materialextraction, relatively loose material, such as thrombus, in the generalproximity to opening 50 would be drawn through opening 50. It should beappreciated and understood that configurations in which aspiration lumen21 communicates directly with opening 50 not by way of materialcollection chamber 90, configurations not shown, could be used and isanother preferred embodiment of this application.

Referring now to FIGS. 5D and 5E, Grasper 60 has been fully retractingcausing full retraction of plunger assembly 65 to retracted position P3.During retraction, negative pressure continued to be created inaspiration chamber 72 and this suction is communicated from aspirationchamber 72 through handle aspiration lumen 78 and its internal valve,aspiration valve 79, into aspiration lumen 21, through materialcollection chamber 90 to opening 50, similar to the suction created asplunger assembly 65 retracts from advanced position P1 to intermediateposition P2. Fluid communication, in other words the effect of thenegative pressure, remains to be cut off from waste exit 81 by theaction of waste valve 82 oriented to prevent flow from waste exit 81into aspiration chamber 72. Movement of plunger assembly 65 fromintermediate position P2 to retracted position P3 has now caused linkage30 to also retract, caused by an urging force generated by proximal edge67 of plunger 66 pushing on linkage projection 36 of linkage 30,simultaneously causing sliding member 100, fixedly attached to the endof linkage 30, to also retract. The retraction of sliding member 100 issuch that the proximal longitudinal portion of sliding member 100resides within controllably arcuate segment 40 and sliding member 100 isof sufficient rigidity to cause controllably arcuate segment 40 totransition from its normally biased curved geometry to the relativelystraight geometry of sliding member 100. The material that waspreviously drawn via suction through opening 50 is pushed away fromopening 50 into material collection chamber 90 as the sliding member 100is retracted by plunger assembly 65 moving from intermediate position P2to retracted position P3.

With grasper 60 in the fully retracted position, as represented in FIGS.5D and 5E, plunger assembly 65 as well as sliding member 100 are alsoretracted and controllably arcuate segment 40 is in a relativelystraight geometry. In this state, the catheter device 10A could beremoved from patient's body and the procedure completed. Alternatively,additional steps of an alternative procedure may be performed whereinadditional one or more cycles of changing controllably arcuate segment40 from straight to bowed geometries and back, appropriately applyingsuction and retraction of sliding member 100 moving material away fromopening 50. Performance of various components and assemblies of catheterdevice 10A for such additional steps are described immediatelyherebelow.

Referring now to FIGS. 5F and 5G, grasper 60 has been advanced, causingplunger assembly 65 to advance from retracted position P3 to secondintermediate position P4. Proximal edge 67 of plunger 66 has moved awayfrom linkage projection 36 of linkage 30 and shaft projection 62 hasreached and come in contact with linkage projection 36 such that furtheradvancement of plunger assembly 65 will cause linkage 30 to advance.Linkage 30 did not yet advance as plunger assembly 65 advanced fromretracted position P3 to intermediate position P4 therefore slidingmember 100 remains in its fully retracted position wherein the proximalportion of sliding member 100 is contained within a lumen ofcontrollably arcuate segment 40 such that controllably arcuate segment40 is in a relatively straight geometry.

Advancement of plunger assembly 65 causes positive pressure to begenerated in aspiration chamber 72 causing fluid and other material tobe evacuated from aspiration chamber 72 thru waste valve 82 and wasteexit 81 and into waste chamber 80. One way valve, aspiration valve 79prevents the fluid and other material contained in aspiration chamber 72from entering aspiration lumen 21.

Further advancement of plunger assembly 65 from second intermediateposition P4 to advanced position P1, shown in FIGS. 5 and 5A, continuethe generation of positive pressure to further evacuate the equivalentvolume of fluid and material from aspiration chamber 72 into wastechamber 80. In addition to the positive pressure and materialevacuation, linkage 30 is advanced. Because of the initial contactbetween shaft projection 62 and linkage projection 36 that occurs whenplunger assembly 65 reaches second intermediate position P4, continuedadvancement to advanced position P1 causes linkage 30 to advance due toan urging force placed upon linkage projection 36 by shaft projection62. Referring back to FIGS. 5 and 5A, when grasper 60 is fully advanced,its proximal end making contact with the distal end of handle 70,linkage 30 is fully advanced causing sliding member 100 to be fullyadvanced. As sliding member is advanced, the proximal portion moves outof controllably arcuate segment 40 allowing controllably arcuate segment40 to transition from a relatively straight geometry to a relativelyarcuate or bowed geometric shape.

FIG. 6 depicts another preferred embodiment of catheter device of thepresent invention which is similar to the catheter device 10 of FIGS. 1Aand 1B with grasper 60, linkage 30 and sliding member 100 all in a fullyadvanced position. Accordingly, elements of this embodiment which aresimilar to elements of catheter device 10 of FIGS. 1A and 1B arereferenced with the same reference numerals. Referring specifically toFIG. 6, catheter device 10B is shown with controllably arcuate segment40 in its maximally straight geometry, and in this particular alsopreferred embodiment, controllably arcuate segment 40 is naturallybiased to be in a maximally straight geometry as opposed to the normallycurved bias of FIGS. 1A and 1 b. Catheter device 10B includes anaspiration chamber 72 included in handle 70. Catheter shaft 20 isfixedly attached to handle 70 while creating a fluid path fromaspiration port 75, into aspiration chamber 72 and continuing throughaspiration lumen 21 to material collection chamber 90. Materialcollection chamber 90 is in fluid communication with opening 50 ofcontrollably arcuate segment 40 and located proximal to opening 50. Asshown in FIG. 6, material collection chamber 90 may be a simplecontinuation of aspiration lumen 21, or material collection chamber 90may have a specific geometry or cavity-like structure while still influid communication with aspiration lumen 21. Material collectionchamber may alternatively be fluidly isolated from aspiration lumen 21such as by way of an integrated valve that allows aspiration lumen 21 tobe in fluid communication with opening 50 when vacuum or suction isapplied by way of aspiration port 75.

Present within an internal lumen of catheter shaft 20 is a flexibleshaft, linkage 30, which is preferably a hollow tube permitting aguidewire to be inserted through its internal lumen, linkage lumen 31.Linkage 30 may be constructed of a flexible metal, such as a flexiblesteel hypotube, or a superelastic material such as Nitinol, a nickeltitanium alloy in its superelastic state. Alternatively, linkage 30 maybe constructed of a flexible plastic tube. As shown in FIG. 6, anopening around linkage 30 provides fluid communication betweenaspiration chamber 72 and aspiration lumen 21. At its proximal end,linkage 30 is fixed to grasper 60 which controls the advancement andretraction of linkage 30 and its connected components. Linkage 30 isfixed at its distal end to sliding member 100. The grasper 60, linkage30 and sliding member 100 are shown in the fully advanced position andthe controllably arcuate segment 40 is shown in a maximally bowedgeometry. Sliding member 100 has a beveled, sharpened or otherwisetapered end, tapered cutting end 102 which faces opening 50 such thatwhen sliding member 100 is retracted, material protruding throughopening 50 can be severed from attached material located within opening50 to prevent jamming of sliding member 100. In alternative embodiments,wherein opening 50 is distal to sliding member 100, tapered cutting end102 would be located on the opposite end of sliding member 100, thedistal end, such that when sliding member 100 is advanced, materialprotruding through opening 50 is similarly severed.

Grasper 60 surrounds and is fixedly attached to linkage 30. The proximalend of linkage 30 includes guidewire opening 32 into which a guidewirecan be placed and from which a guidewire can exit if inserted from theother end. Linkage lumen 31 may include a valve, not shown, in its pathto prevent leakage of blood or other fluid once catheter device 10B isinserted into the body. Alternatively, the diameter of linkage lumen 31is chosen to be as small as possible, slightly larger than the outsidediameter of the guidewire it is to be placed over. Linkage 30 entershandle 70 such that a relatively fluid tight seal is created, such asthat created with an elastomeric o-ring which seals between handle 70and linkage 30 yet allows linkage 30 to slide back and forth as grasper60 is advanced and retracted as was described in reference to FIGS. 3and 3 a. Linkage 30 may include a mechanical stop, such as linkage stop35, included on the outer diameter of linkage 30 to limit the maximumretraction distance of grasper 60. Linkage stop 35 is positioned alongthe outer diameter of linkage 30 such that when grasper 60 is retractedtill linkage stop 35 is in contact with the inside surface of aspirationchamber 72, sliding member 100 is properly positioned withincontrollably arcuate segment 40, the advanced position shown in anddescribed with FIGS. 6, 6A and 6B. In this preferred embodiment, thedistal end of sliding member 100 extends beyond the distal end ofcatheter device 10 throughout the fully advanced and fully retractedtravel of grasper 60 and linkage 30.

As mentioned previously, the catheter device 10B of FIG. 6 isconstructed such that the normal bias of controllably arcuate segment 40is a straight geometry, generally along the longitudinal axis ofcatheter shaft 20. It should be noted that in this and all otherembodiments of this application, controllably arcuate segment 40 whilenaturally biased to be bowed or straight, is relatively flexible, i.e.flexible enough relative to its length to allow insertion of catheterdevice 10B through the body, such as through the vascular system,without disrupting or otherwise damaging the inner walls of conduitssuch as blood vessels. This flexibility may or may not be compromisedwhen sliding member 100 is retracted to reside within a lumen ofcontrollably arcuate segment 40. The catheter device 10B of FIG. 6further includes means to change controllably arcuate segment 40 fromits naturally straight geometry to a relatively bowed or curvedgeometry. Various curving means are described in accordance with theFIGS. 6, 6A, 6B and 7 through 10 however it should be understood andconsidered within the scope of this application, that numerousalternatives are possible to cause, based on controls that can beactivated from the proximal end of catheter device 10, such as those onor near handle 70, shape transformation of controllably arcuate segment40.

Again, referring specifically to FIG. 6 and additionally to FIGS. 6A and6B, contained or embedded within the walls of controllably arcuatesegment 40 is curving element 110 which can on command convertcontrollably arcuate segment 40 from a relatively straight geometry to arelatively bowed geometry. The curving element 110 is preferably anelectrically activatable component such as a piezo element, anelectromagnetic assembly or a shaped memory component, such as a shapedmemory alloy or shaped memory polymer. When connected to an energysource applying a voltage and or a driving current, curving element 110changes its shape thus causing controllably arcuate segment 40 to alsochange shape. Curving element 110 is attached to controls in handle 70by arcuate control wires 113, preferably flexible electrical conductors,such as wires, embedded in or on the inside diameter of shaft 20. At theproximal end of arcuate control wires 113 is an energy source, powersource 112, which is preferably an integrated battery or batteryassembly. Completing the electrical circuit is a switch, arcuate controlswitch 111, which when depressed by the user, fully connects powersource 112 to curving element 110 thus causing both curving element 110and controllably arcuate segment 40 to change geometry such as changingfrom a relatively straight geometry to a relatively curved geometry. Itshould be noted, however, that a similar configuration of curvingelement 110 can be used to change controllably arcuate segment 40 from arelatively bowed geometry to a relatively straight geometry when poweris applied to curving element 110. FIG. 6A depicts curving element 110without power attached, i.e. arcuate control switch 111 not depressed,and controllably arcuate segment 40 in a relatively straight geometry.FIG. 6B depicts curving element 110 with power attached, i.e. arcuatecontrol switch 111 depressed by the operator, and controllably arcuatesegment 40 in a relatively bowed geometry. It may be desirable to add anindicator, not shown, to indicate the geometric shape of controllablyarcuate segment 40 when the catheter device of the present invention isinserted into the patient, i.e. when the controllably arcuate segment 40cannot be directly visualized. The shape indicating means, all notshown, may include a visual indicator, such as an indicator lightlocated on the handle of the device, and or an audio indicator such asan electronic buzzer which generate feedback to the user to indicate thegeometric shape of controllably arcuate segment 40. For example, sincethe catheter device of the present invention is generally not to beadvanced or retracted unless controllably arcuate segment 40 is in arelatively straight geometric shape, an audio indicator may be includedwhich creates a buzzing sound whenever the controllably arcuate segment40 is not in a relatively straight geometric shape.

Still referring to FIG. 6, sliding member 100 is shown in its fullyadvanced position, since grasper 60 is fully advanced causing linkage 30to also be fully advanced. Controllably arcuate segment 40 has anormally straight geometric bias, and is converted to a relatively bowedgeometry by activation of curving element 110 as well as being convertedback to a relatively straight geometry by deactivation of curvingelement 110. Unlike the catheter device 10 of FIG. 1, sliding member 100does not have to be used to change the shape of a pre-curvedcontrollably arcuate segment 40. Sliding member 100 in FIG. 6 stillhowever provides the function of moving material away from opening 50when retracted, aided by a sharpened leading edge, tapered cutting end102. Since sliding member 100 of catheter device 10B of FIG. 6 does notprovide the function of changing the shape of controllably arcuatesegment 40, sliding member 100 can be made of very flexible materialswhich do not impact the shape of controllably arcuate segment 40 whensliding member 100 enters and exits the lumen of controllably arcuatesegment 40. When controllably arcuate segment 40 is in its maximallybowed geometry as caused by curving element 110, and vacuum is appliedat opening 50 thus drawing material through opening 50, sliding member100 can be retracted pushing material away from opening 50 withoutaltering the shape of controllably arcuate segment 40.

Referring specifically to FIGS. 6A and 6B, catheter shaft 20 has adiameter, catheter diameter D, near its distal end. When controllablyarcuate segment 40 has a relatively curved geometry, the maximum offsetfrom the outside diameter of catheter shaft 20 is defined as axialoffset AO. In cardiovascular applications, catheter diameter D willtypically between 1.5 and 4 millimeters. Curving element 40 has a lengthand radius of curvature of both its proximal and distal arc that arechosen to create a group of products that provide a wide range of valuesfor axial offset AO. Typically catheter diameter D is chosen to beapplicable to navigate the tortuosity of the vasculature to reach thetarget lesion to be treated, and axial offset AO is chosen to cause theopening 50 to be in contact, with sufficient force, to the target lesionwhen controllably arcuate segment 40 is in its maximally bowed geometry.Some applications, such as interventional neurological procedures, mayrequire much smaller diameters and axial offsets, while otherapplications may permit or require larger diameters and offsets.

FIG. 7 depicts another preferred embodiment of catheter device of thepresent invention which is similar to the catheter device of FIG. 6 withan integral means for curving controllably arcuate segment 40, curvingmeans 110 embedded within the walls of controllably arcuate segment 40.As described previously, curving means 110 can be of various shapealtering forms, such as shaped memory components, piezo components,electromagnetic assemblies and other electrically and non electricallyactivated shape changing components known to those of skill in the art,and all considered within the scope of this application. Curving means110 is attached to electrical controlling wires, arcuate control wires113 which connect to power and switching means contained in the proximalhandle. Controllably arcuate segment 40 also includes one or more holes,opening 50 which are in fluid communication with a chamber, materialcollection chamber 90, into which material received through opening 50is pushed by tapered cutting end 102 of sliding member 100. Linkage 30and sliding member 100 are shown in their fully advanced position. FIG.7 defines a cross-sectional view A-A directed toward the distal end ofcatheter shaft 20.

FIG. 8 shows a preferred embodiment of the curving element 110 locatednear the distal end of catheter shaft 20 shown at the cross-sectionalview A-A of FIG. 7. The curving element 110 of FIG. 8 has a tubularconstruction, with a circular cross section contained within the wallsof catheter shaft 20 in the region of controllably arcuate segment 40.Alternatively but not shown, curving element 110 may be outside of thewalls within the lumen of catheter shaft 20. Curving element 110 wouldinclude a thru-hole or opening, curving element opening 115 which isaligned with opening 50 to allow material to pass through opening 50 andcurving element opening 115 from the outside of catheter shaft 50 to aninner lumen of catheter shaft 20 when suction is applied. Curvingelement 110 is controlled from the proximal end of catheter device 10,such as has been described hereabove, and its tubular structure changesshape to cause controllably arcuate segment 40 to change from arelatively straight geometry to a relatively bowed geometry or causescontrollably arcuate segment 40 to change from a relatively bowedgeometry to a relatively straight geometry. Curving element 110 may beattached to electrical wires connected to a switch and power supply asdescribed in FIGS. 6, 6A and 6B or other activation means controllablefrom the proximal end of catheter device 10.

FIG. 9 shows another preferred embodiment of the curving element 110located near the distal end of catheter shaft 20 shown at thecross-sectional view A-A of FIG. 7. The curving element 110 of FIG. 8has a filament-like construction, with a chord-like cross sectioncontained within the walls of catheter shaft 20 in the region ofcontrollably arcuate segment 40. Alternatively but not shown, curvingelement 110 may be outside of the walls within the lumen of cathetershaft 20. Curving element 110 would be placed away from opening 50 suchthat material will pass through opening 50 from the outside of cathetershaft 20 to an inner lumen of catheter shaft 20 when suction is applied.Curving element 110 is controlled from the proximal end of catheterdevice 10, such as has been described hereabove, and its filament-likestructure changes shape to cause controllably arcuate segment 40 tochange from a relatively straight geometry to a relatively bowedgeometry or cause controllably arcuate segment 40 to change from arelatively bowed geometry to a relatively straight geometry. Curvingelement 110 may be attached to electrical wires connected to a switchand power supply as described in FIGS. 6, 6A and 6B or other activationmeans controllable from the proximal end of catheter device 10.

FIG. 10 shows yet another preferred embodiment of the curving element110 located near the distal end of catheter shaft 20 shown at thecross-sectional view A-A of FIG. 7. The curving element of FIG. 10consists of two curving elements, first curving element 110A and secondcurving element 110B both of which have a filament-like construction,with a chord-like cross section contained within the walls of cathetershaft 20 in the region of controllably arcuate segment 40. First curvingelement 110A and second curving element 110B may have different lengthsand or cross-sectional geometries, and they may be controlled togetheror independently. Alternatively but not shown, first curving element110A and or second curving element 110B may be outside of the wallswithin the lumen of catheter shaft 20. Both first curving element 110Aand second curving element 110B would be placed away from opening 50such that material will pass through opening 50 from the outside ofcatheter shaft 50 to an inner lumen of catheter shaft 20 when suction isapplied. Both first curving element 110A and second curving element 110Bis controlled from the proximal end of catheter device 10, such as hasbeen described hereabove, and the filament-like structures change shapeto cause controllably arcuate segment 40 to change from a relativelystraight geometry to a relatively bowed geometry or cause controllablyarcuate segment 40 to change from a relatively bowed geometry to arelatively straight geometry. Independent control of first curvingelement 110A and second curving element 110B can be used to createmultiple states of curvature for controllably arcuate segment 40 such asto cause different axial offsets as has been described hereabove. Bothfirst curving element 110A and second curving element 110B may beattached to electrical wires connected to a switch and power supply asdescribed in FIGS. 6, 6A and 6B or other activation means controllablefrom the proximal end of catheter device 10.

Referring collectively to all of the figures and their descriptionsincluded hereabove, the catheter devices of the present invention areintended to enter the body of a mammalian patient, such as viapercutaneous or surgical means, to perform a therapeutic or diagnosticprocedure. To properly accomplish these types of procedures, the deviceswould be provided in a sterile condition, with appropriate packaging tomaintain sterility up until use. In addition, the catheter device may bepart of a kit, with numerous other components applicable to theprocedure, such as a guide catheter and guidewire, included in thesterile packaging or in separate sterile packaging included in the samepurchased kit. The catheter device of the present invention may beinserted into the body over a standard interventional guidewire toassist in advancing the device to the intended location. The variousfigures and included text have described configurations wherein thedevice has a guidewire that enters and exits the catheter at or near thedistal and proximal ends. Devices with this configuration utilizeguidewires which are approximately twice the length of the over the wiredevice to allow placement of the device with a pre-placed guidewire andwithdrawal of the device leaving the guidewire in place. In analternative catheter design, also considered within the scope of thisapplication, near the distal end of the catheter device is included asmall length of material attached to the catheter shaft, similar to asidecar, which consists of a single lumen and its surrounding walls. Inthis configuration, a smaller length guidewire can be inserted throughthe lumen of the sidecar only, not through the entire length of thecatheter device, and the catheter device advanced and retracted overthis shorter guidewire.

The catheter of this invention may be a precursor to other materialremoval or treatment procedures such as balloon angioplasty, stenting orother procedures. Although this system was described specifically for asaphenous vein graft, it is readily applicable to any stenosis of avessel or other applicable tubular body conduit in the body. Forexample, the catheter device of the present invention could be used toopen stenoses in the carotid artery, dialysis fistulas, peripheralvasculature, etc. Although the present invention has only described theremoval of plaque or thrombus from human vessels, the catheter device ofthe present invention could also be used to remove other stenotic oroccluding tissue from ducts such as the ureters or the fallopian tubes.Mammalian patients would include both humans and other animals. Also,although percutaneous procedures have been described, catheter devicesof the present invention, particularly those with larger diameters orwhere the intended site is a body conduit that is not a blood vessel,could be used intraoperatively by surgical incision into an access pointappropriate for the intended site.

In order to draw material through opening 50, a negative pressure isapplied to the inner side of opening 50 which is communicated through alumen within catheter shaft 20. Various means of causing this negativepressure, also referred to synonymously throughout this application asvacuum, suction or aspiration, can be used. Vacuum generators can beintegral to catheter device such as has been described in reference toFIGS. 5 and 5A through 5G, or external vacuum generators can be attachedincluding a simple syringe to more complex aspiration and materialcollection devices. The various embodiments described hereabove show afluid communication between aspiration lumen 21 and opening 50 that isconnected via material collection chamber 90. It should be understoodand considered within the scope of this application that aspirationlumen 21 can be connected directly to opening 50 and material collectionchamber 90 isolated from the negative pressure by way of a valve orother means. This particular configuration is another preferredembodiment and may be useful in avoiding clogging or otherwiseobstructing aspiration lumen 21 from being able to apply the appropriateamount of suction at opening 50. Opening 50 may include one or moreholes with various cross-sectional geometries and tapers. Opening 50 maybe designed to be fluidly closed when controllably arcuate segment 40 isin a relatively straight geometry and open as controllably arcuatesegment 40 transforms to a bowed geometry, or opening 50 may be fluidlyopen at all times.

Also, it is intended for opening 50 to be brought in close proximity tothe material to be removed, and apply a finite amount of force to thewall of the body conduit or on the material to be removed by the portionof catheter shaft 20 immediately surrounding the opening, each featureintended to enhance the ability of the vacuum to draw material throughopening 50. This proximity is achieved when controllably arcuate segment40 is changed from a relatively straight geometry to a relatively bowedgeometry. The various embodiments described hereabove show variousconfigurations of relatively bowed geometries, however it should beunderstood and considered within the scope of this application that anygeometry that causes an axial offset of opening 50 from the outersurface of the majority of catheter shaft 20 would function to bringopening 50 towards the wall of the biological conduit into which it isinserted. It also should be understood that controllably arcuate segment40 may be able to assume multiple geometries with multiple axial offsetsor other geometric configurations that provide specific advantages forthe various anatomies and disease states and locations being treated. Itis preferred that a portion of catheter shaft 20 extend beyondcontrollably arcuate segment 40 such that a portion of non shapealtering catheter shaft exists between the distal tip of catheter shaft20 and controllably arcuate segment 40.

In the various procedures described hereabove, it may be desirable toremove material such as thrombus that may be present at the end ofcatheter shaft 20. To facilitate this function, a lumen may be providedto support simple suction removal from the end of the catheter shaft 20,or an internal mechanism or a removable core, such as linkage 30 andsliding member 100 may be removable to create a lumen to which suctioncan be applied to remove material from the distal end of the catheter.

In another preferred embodiment of the present invention, a catheterdevice includes an elongate catheter body or shaft having a proximal endand a distal end, a controllably arcuate segment, an aspiration chamberlocated near the proximal end of the catheter shaft, a controllablyarcuate segment including at least one opening and an aspiration lumenin fluid communication with the aspiration chamber and one or more ofthe openings in the controllably arcuate segment. This particularcatheter device may include a separate lumen to allow over the wireinsertion and a lumen to allow aspiration from the distal tip of thecatheter.

The various embodiments described hereabove, such as those described inreference to FIGS. 5 and 5A through 5G, have described a catheter device10A wherein retraction of grasper 60 causes linkage 30 and thus slidingmember 100 to also retract to accomplish one or more functions includingmoving material away from opening 50 in a proximal direction and intomaterial collection chamber 90 which is proximal to opening 50. Itshould be appreciated and considered within the scope of thisapplication wherein material collection chamber 90 is distal to opening50, and advancement of grasper 60 causes advancement of linkage 30 andthus sliding member 100 such that material is moved away from opening 50in a distal direction into material collection chamber 90. In thisparticular configuration, sliding member 100 would not exit the distalend of catheter shaft 20 but would remain within a lumen of cathetershaft 20 in both its fully advanced and fully retracted positions.Similar to other embodiments, material is drawn through opening 50 viasuction from the proximal end of catheter device 10, such as viaaspiration port 75 and aspiration lumen 71.

It is to be understood and appreciated that the invention has beendescribed herein with reference to certain presently preferredembodiments and examples only, and no effort has been made toexhaustively describe all possible embodiments and examples of theinvention. Indeed, as those killed in the art will appreciate, variousadditions, deletions, modifications and variations may be made to theparticular embodiments and examples described hereabove withoutdeparting from the intended spirit and scope of the invention. Inaddition, wherever steps of a method have been described, there is nointent for a required order unless specifically described. Accordingly,it is intended that all such additions, deletions, modifications andvariations be included within the scope of the following claims.

1. A catheter for insertion into a biological conduit comprising: anelongate catheter shaft having a proximal end and a distal end forinsertion into the biological conduit, the catheter shaft comprising: amaterial collection chamber located within the catheter shaft, acontrollably arcuate segment adjacent to the distal end configured toselectively transition between a relatively straight shape and a bowedshape, the controllably arcuate segment defining an opening in the formof a hole that is located at a convex portion of the controllablyarcuate segment when the arcuate segment takes the bowed shape, whereina portion of the controllably arcuate segment having the opening isconfigured to maintain a substantially constant cross section throughoutthe transition; and a sliding member movably disposed within the shaftand configured to selectively traverse the opening to move an occlusivematerial received through the opening into the material collectionchamber and away from said opening, wherein movement of the slidingmember past the arcuate segment and to the distal end allows for thetransition from the relatively straight shape to the bowed shape.
 2. Thecatheter of claim 1 further comprising suction means near the proximalend, said suction means in fluid communication with the opening in thecontrollably arcuate segment.
 3. The catheter of claim 1 furthercomprising an aspiration chamber near the proximal end, said aspirationchamber in fluid communication with the material collection chamber. 4.The catheter of claim 3 further comprising a one-way valve locatedbetween the aspiration chamber and the material collection chamber, saidvalve oriented to allow material to flow from the material collectionchamber to an aspiration port extending from the aspiration chamber. 5.The catheter of claim 3 wherein the aspiration chamber includes anintegrated plunger assembly.
 6. The catheter of claim 1 wherein thematerial collection chamber is proximal to the controllably arcuatesegment.
 7. The catheter of claim 1 further comprising a materialextraction lumen between the distal end of the catheter shaft and anaspiration port located on the proximal portion of the device.
 8. Thecatheter of claim 1 wherein the controllably arcuate segment has anormally bowed bias.
 9. The catheter of claim 8 wherein positioning ofthe sliding member within the controllably arcuate segment causes saidarcuate segment to be relatively straight.
 10. The catheter of claim 1wherein the sliding member has a cutting edge on the end facing theopening in the controllably arcuate segment.
 11. The catheter of claim 1wherein the sliding member is attached to a flexible shaft, said shafttraversing the length of the catheter and said sliding member advancedand retracted by advancing and retracting said shaft from controlslocated on the proximal end of said catheter.
 12. The catheter of claim1 further comprising a rotational orientation element.
 13. A catheterfor insertion into a biological conduit comprising: an elongate cathetershaft having a proximal end and a distal end for insertion into thebiological conduit, the catheter shaft comprising: a controllablyarcuate segment adjacent to the distal end configured to selectivelytransition between a relatively straight shape and a bowed shape, thearcuate segment defining an opening in the form of a hole that islocated at a convex portion of the arcuate segment when the arcuatesegment takes the bowed shape, wherein the hole is configured to receivean occlusive material when the arcuate segment takes the bowed shape anda portion of the arcuate segment having the opening is configured tomaintain a substantially constant cross section throughout thetransition; an aspiration chamber located near the shaft proximal end,the aspiration chamber having an aspiration port configured to receive avacuum input; an aspiration lumen configured to form a vacuum pathbetween the aspiration chamber and the opening when the vacuum input isapplied to the aspiration port; and a sliding member movably disposedwithin the shaft and configured to selectively traverse the opening tomove the occlusive material received through the opening away from saidopening and toward the aspiration chamber, wherein movement of thesliding member past the arcuate segment and to the distal end allows forthe transition from the relatively straight shape to the bowed shape.14. A catheter for insertion into a biological conduit comprising: anelongate catheter shaft having a proximal end and a distal end and alongitudinal axis extending between the proximal and distal end, thecatheter shaft comprising: a material collection chamber located withinthe catheter shaft, a controllably arcuate segment configured toselectively transition between a relatively straight shape and a bowedshape, the controllably arcuate segment defining an opening in the formof a hole that is located at a convex portion of the controllablyarcuate segment when the arcuate segment takes the bowed shape, whereina portion of the controllably arcuate segment having the opening isconfigured to maintain a substantially constant cross section throughoutthe transition, substantially straight portions on both sides of thearcuate segment, wherein the straight portions are substantiallyco-axial with the longitudinal axis while the arcuate segment is in thebowed shape; and a sliding member movably disposed within the shaft andconfigured to selectively traverse the opening to move an occlusivematerial received through the opening into the material collectionchamber and away from said opening.